Beneficiating naphthas



Patented Mar. 11, 1941 AT-ENT OFFICE BENEFICIATING NAPHTHAS Robert E. Burk, Cleveland Heights, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio,

a corporation of Ohio No Drawing. Application September 10, 1938, Serial No. 229,293

7 Claims. (Cl. 196-13) Naphthas from mineral oil sources in general are mixtures of hydrocarbons some of which have low anti-knock value and some high, and again some hydrocarbon constituents have low solvent power, while others have high solventicity. As

a practical consequence, naphthas which are employed as motor fuel or for the preparation of motor fuel, represent undesirably low averages in operation, and it is quite a prevalent custom to help out in this respect by resort to anti-knock chemicals such as lead tetra-ethyl. Similarly also where naphthas are to be employed. for solvent uses, the products are of such character as tobe inapplicable for some uses where their properties otherwise would render them highly desirable. In accordance with the present invention, naphthas may be beneficiated however, such as to render them of much higher desirability as regards anti-knock property, where destined for internal combustion engine usage, and for increasing the solvent value of products destined for solvent usages, 1

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various Ways in which the principle of the invention may be employed.

The naphtha to be treated, may vary as to its boiling range, in accordance with the usage in view. Thus, for carbureter-fed internal combustion engine usage, a distillate having a finished end point of 437 F., or in some instances lower, is employed, and for other fuel purposes the end point may be higher, and again for solvent purposes the boiling range may involve wide or narrow cuts, and with lower or higher end point than in the case of naphthas for internal combustion engine usage. The distillate is treated with a solvent having in general a higher boiling point than the end point of the distillate, and

being operable at an elevated working temperature and being separable on cooling, and withal having selectivity as between high and low antiknock constituents or high and low solvent constituents. For such selective extractive solvents,

I may apply for instance naphthylamines, phenylenediamine, diaminotoluenes, other aromatic amines, alpha naphthol, dihydroxy diphenyls, chlorinated phenols, nitro-anilines, acetanilid, alkyl amino-phenols, benzyl amino-phenols, etc. or mixtures of them; and as a further refinement of the invention I may apply such a selective solvent as to in conjunction with the separation of the hydrocarbon constituents also at the same time provide a sweetening treatment, or remove poisons which would act adversely against 5 catalysts employed in a later stage; and thus by such agents as naphthylamine, phenylenediamine, diphenyl diamines, other aromatic amines, acetanilid, alpha naphthylamine, diphenyl amine, etc., or mixtures of them, such conjoined actions become eifective. In the cases where feasible, it is sometimes of advantage to make the distillate cut in such a manner as to in general segregate a first portion containing hydrocarbons of light character, such as of five carbon atoms and bea low, insofar as this goes practicably, and later blend this portion with a higher boiling portion after a selective treatment thereof. The distillate hydrocarbons which are to be treated are subjected to mixture with the treating agent or 20 solvent as above-mentioned, the latter being generally in volume greater than that of the distillate, one to ten volumes for instance, and the distillate and solvent are thoroughly mixed, the temperature being elevated, depending somewhat upon the particular agent used and distillate treated and in general being above and up to 500 F. Solvent mixtures of agent are particularly advantageous. Having thoroughly subjected the distillate to the action of the solvent, the 30 mixture is cooled and allowed to stratify. The settling temperature depends somewhat upon the type of agent employed, and. may in general be 60 to 390 F. In some instances, the first treatment may be carried out with a smaller volume 35 of a solvent depending upon the particular components which are to be attacked. The basicacting types of solvent such as alphanaphthylamine, phenylenediamine etc. also take out hydrogen sulphide, mercaptans, phenols, and active 40 catalyst poisons, and the treatment cycle may be arranged as convenient with apparatus to give stage-wise progressive extraction contact and separation, as in counter current order etc.

Having separated the distillate into extract 45 and extracted portions, one containing especially cyclic hydrocarbons and the other containing especially open chain hydrocarbons, the material which is of low anti-knock value is desirably subjected to molecular rearrangement, as by an ox- 50 ide catalyst, e. g. chromium oxide, at a temperature of about 500 C., for a few seconds. It is to be noticed that in this stage the catalyst is permitted to operate under particularly favorable conditions, the catalyst poisons having been 55.

eliminated in conjunction with the selective separation of the hydrocarbon material. By remixing the very light fraction involving hydrocarbons below those of six carbon atoms, a motor fuel may be constituted which with a particularly favorable boiling range combines remarkably high knock rating. Again, with or without the catalytic rearrangement treatment, naphtha solvents of desired boiling range may be produced, having a remarkable high solvent power for resins and synthetic condensation products ordinarily little affected by naphthas of petroleum type.-

As an example: A naphtha cut destinedfor solvent purposes, and taken from a Midcontinent petroleum and having 48.2 gravity, and showing 14 per cent unsaturates and aromatics by the H2SO4 Kattwinkel test, and aniline point 139 F., is extracted with 1 volumes of a mixture of per cent alphanaphthylamine and 20 per cent m-phenylenediamine, being mixed at a temperature of F. The mixture is allowed to separate, and the rafi'inate is extracted a total of three times with similar volumes of an amine mixture. The hydrocarbon extract obtained contains 39 per cent of aromatics and unsaturates and has a gravity 42.3 and aniline point As another example: A similar naphtha is treated with three extractions employing alphanaphthylamine in 1 times the volume of the naphtha, and the temperature being F. The extract has a gravity 47.7, aniline number 129, and contains 22 per cent aromatics and unsaturates.

As another example: A naphtha treated with alphanaphthylamine similarly extracted at 113 F. segregated 47.5 per cent of the aromatics.-

As another example: A naphtha treated with a mixture of 85 per' cent alphanaphthylamine and 15 per cent of rn-phenyldiamine, in three treatments, at a temperature of 120 F., in ratio of three volumes of the solvent to two volumes of the naphtha, yields a top layer of 52 gravity and 151.5 aniline point, and a bottom layer of 43.5 gravity and 98 aniline point.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than about six carbon atoms, mixing with the distillate a selective solvent made up of a major portion of alphanaphthylamine and a minor proportion of metaphenylenediamine, .at elevated temperature, lowering the temperature and allowing layer formation to occur, separating the, respective layers of distillate and solvent, washing the petroleum distillate portion with water, and reforming the distillate portion by subjecting to heat in the presence of a catalyst.

2. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than about six carbon atoms, mixing with the distilate a selective solvent made up of a major portion of alphanaphthylamine and a minor proportion of metaphenylenediamine, at elevated temperature, and allowing layer formation to occur, separating the respective layers of distillate and solvent, washing the petroleum distillate portion with water, and reforming the distillate portion by subjecting to heat in the presence of a catalyst.

3. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than about six carbon atoms, mixing with the distillate a selective solvent made up of a major portion of alphanaphthylamine and a minor proportion of metaphenylenediamine, at elevated temperature, and allowing layer formation to occur, separating the hydrocarbon layer from the selective solvent layer, and re-forming the hydrocarbon portion by subjecting to heat in the presence of a catalyst.

4. In a process of the character described, mixing with a petroleum distillate a selective solvent made up of a major portion of alphanaphthylamine and a minor proportion of meta phenylenediamine, at elevated temperature, al-

lowing layer formation to occur, and separating u the solvent and distillate layers.

5. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than six carbon atoms, mixing the distillate with an organic amine selective solvent having a boiling point not lower than about 450 F. from the group consisting of alphanaphthylamine, betanaphthylamine, phenylenediamines and diphenyl amines, washingthe petroleum distillate portion with water, and re-forming the distillate portion by subjecting to heat in the presence of a catalyst.

6. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than six carbon atoms, mixing the distillate with an organic amine selective solvent having a boiling point not lower than about 450 F. from the group consisting of alphanaphthylamine, betanaphthylamine, phenylenediamines and diphenyl amines, and allowing layer formation to occur, separating the solvent and distillate, and reforming the distillate portion.

'7. In a process of the character described, substantially eliminating from a light petroleum distillate hydrocarbons of less than six carbon atoms, mixing the distillate with an organic amine selective solvent having a boiling point not lower than about 450 F. from the group consisting of alphanaphthylamine, betanaphthylamine, phenylenediamines and diphenyl amines, and allowing layer formation to occur, and separating the solvent and distillate.

ROBERT E. BURK. I 

